Climate variability in the Paraguay Basin

CAMILA PRUDENTE; FEDERICO ROBLEDO

Christchurch

Conferencia; International Conference on Southern Hemisphere Meteorology and Oceanography; 2022

American Meteorological Society

Climate patterns forced by tropical sea surface temperature modulate the interannual variability of the river levels at La Plata Basin (LPB) and water excesses or deficits that impacts on the urban population of coastal cities and on agricultural and livestock production. In particular, over the Paraguay basin, a sub-basin of the LPB, there are not many studies on climate variability. The goal of this study is to explore the covariability between the water level of the Paraguay River and precipitation in the region, throughout the 20th century to the present, and its relationship with climate patterns. The covariability between seasonal precipitation and monthly river level was analyzed in the period 1976-2015 using Singular Values ​​Decomposition methodology. The first mode of covariability evidenced a direct relationship between precipitation and water level in the entire basin. On the other hand, the second mode exhibited a dipole in the precipitation in a northwest-southeast direction that decouples the response of the Paraguay River. The water level in the upper basin was significantly related to the precipitation of the center-west-north of the basin, whereas in the middle and lower basin, it was related to the precipitation over the southeast of the Paraguay Basin. The relationship between modes of covariability and climate patterns was explored (El Niño-Southern Oscillation, among others)